Further parameters can be set by activating the "Advanced" button:

 

 

Output: File

The name of the output file is defined here. The default setting is the name out.e.

 

Fitting of the saturated thickness (2D) or partially saturated computation (3D)

For 3D models, it is possible to take into account the partially saturated areas (see calculation of the free surface). The corresponding element factors for the unsaturated elements are calculated from the specified target state. For horizontal models, it is also possible to adjust the thickness, which is then calculated from the measured groundwater surface and the model subsurface (taking into account any defined maximum thickness). However, this only makes sense if the thicknesses recorded in the model test may not correspond to the water-filled thickness in some elements (which should not normally be the case).

 

Attenuation of the K-value change of an element

Damping is recommended as the iteration oscillates slightly in the case of a 'bad' initial state and K values of neighbouring elements can fluctuate extremely. Local damping of the change in the relative K value by taking into account the K values in the neighbouring elements is carried out automatically and has already been described above.

For a simple damping of the K-value change from one iteration to the next, the user specifies an attenuation factor at this point.

Instead of the newly calculated K value kn+1 (see iterative calibration)

 

k_neu = k_n + x * (k_n+1 - k_n) mit 0 < x <= 1

 

is used. The default setting is an attenuation factor of x = 0.5.

 

Equation solver

Either the iterative PCG solver or the direct Cholesky equation solver can be selected as the equation solver. Due to its advantages in terms of computing time and memory space, the iterative equation solver is recommended from approximately 500 nodes and more. In contrast to the direct method, the solution is not calculated exactly; however, the error is usually negligible. An accuracy check can be carried out using the mass balance specified in the output file.

 

Calibration results